In a letter to Mr. de Blasio sent earlier this week, Mr. Vacca called on the mayor to allocate an added $200 million to the police department’s operating budget to hire 1,000 new officers. The budget is expected to be presented at the beginning of May.

“New York City is the safest big city in the country, but we have taken the crime reductions our city has experienced for granted for far too long. We can only maintain these gains and build on them with adequate police protection,” Mr. Vacca wrote in the letter, shared with the Observer. “As Commissioner William Bratton has repeatedly said, ‘Police count. Cops matter.’ The taxpayers and law-abiding citizens of our city deserve nothing less than appropriate staffing levels to maintain safer streets and neighborhoods.”

The NYPD’s force is currently down to less than 35,000 people–about 6,000 fewer officers than in 2001.

In an interview, Mr. Vacca argued that Mr. de Blasio’s new focus on the “Vision Zero” traffic safety plan, which includes measures like expanding the city’s highway safety unit, and his focus on community policing, which emphasizes cops on the streets, will stretch the force even more.

“I think that we could be in the position of taking from Peter to pay Paul at this point,” he said. “The reality is all of this is coming from somewhere.”

“I think that we’re kidding ourselves if we are saying as a city that we can do more with less,” he added. “If New York City wants to have new initiatives … we can’t be taking from local precincts that are already stretched power-wise.”

The administration has so far held the line that, while more cops are always great, the city’s low crime rate is evidence the current force size is sufficient.

“I have felt for a long time that when you see that level of effectiveness and you see it on such a sustained basis, it tells us something about the fact that we’re at a good and capable size right now,” Mr. de Blasio told reporters last week when asked about NYPD staffing levels.

Still, he hinted that he might be open to adjustments, adding, “we’ll have more to say around the time of the executive budget.”

At a City Council hearing last month, Mr. Bratton said he was “very concerned” about the current staffing levels, but last week made the case that soaring overtime “effectively gives you the equivalent of those officers on a daily basis.” The NYPD paid out more than $630 million in overtime during fiscal year 2013, almost twice as it spend in fiscal 2001, according to the mayor’s management report.

Mr. Vacca is not the only lawmaker putting growing pressure on the mayor to up the count. In an interview with reporters this week, Public Advocate Letitia James expressed her own concern with the staffing levels, arguing that the city needs to grow the department to keep crime low.

“I’ve heard about commanding officers all throughout the city of New York who are just concerned about the decrease in workforce and the number of officers and rank-and-file who are retiring,” said Ms. James, according to DNAinfo.com. “I think we need to increase the number of police officers.”

Mr. Vacca said he plans to spend the next two weeks pushing for the measure along with his colleagues.